May 19, 1921 mcateE: nomenclature 231 



Recently a set of rules has been proposed in Science,^ the most im- 

 portant requirement of which is that "The type genus of a family or 

 subfamily is the included generic group from the name of which the 

 family or subfamily name was originally^ formed, and is to remain 

 the type genus irrespective of changes in its name." In other words,, 

 the name of the family changes with every change in that of the 

 so-called type genus. Thus if a family or subfamily name had been 

 based on the genus to which the rose-breasted grosbeak is assigned, 

 in following all of the mutations of its type genus it would have been 

 changed to conform with the 5 generic names listed hereunder, during 

 the period that family names have been generally used in ornithological 

 nomenclature: Guiraca, Hedymeles, Goniaphaea, Habia, Zamelodia; 

 and in earlier periods the species has been referred to at least 5 addi- 

 tional genera. The writer does not undertake to say whether or not 

 this is an extreme case ; at any rate it illustrates how the system might 

 work. 



The opposed method of selecting family names is basing each upon 

 that of the oldest included genus. If for any reason the oldest name 

 becomes unavailable the next oldest is used, and so on. It stands to 

 reason that if the bases of family names are exclusively the oldest 

 generic names, there will be fewer nomenclatorial casualties than if 

 any later names are used. For the more recent the name the more 

 likely it is to prove a homonym or synonym. 



In the absence of definite rules on the subject, how has the selec- 

 tion of family names worked out in actual practice in zoology? Un- 

 questionably the general practice has been to use family names based 

 on the earliest available generic names. Whether they were delib- 

 erately selected from this point of view may be questioned, but the 

 evidence is strongly that way, for as will be pointed out in the sequel 

 the chances of general agreement upon family names having priority 

 in themselves are very remote. To illustrate usage in the selection 

 of family names we may cite the "Index Generum Mammalium,"^ in 

 which 159 of the accepted names are based on the oldest generic name 

 (not preoccupied) or upon one of a group of names of the earliest 

 year date, while 34 (chiefly of fossil groups) are not. Of the total 



3 Science, N. S. 52: 142-147. Aug. 13, 1920. 



* Discussion later in this paper shows that it is by no means easy to decide where and 

 when the family name was "originally formed." Priority in family names is not the com- 

 paratively simple matter that it is in generic names. 



»T. S. Palmer, N. A. Fauna 23. 1904. 



